Tractor-mounted loader



Oct. 3, 1950 C, w, Mo'r'r 2,524,203

TRACTOR-MOUNTED LOADER Filed July 29, 1948 Y 2 Sheets-Sheet 2 WMHHHHMHF IN VEN TOR. @mi Z/VO Zf Pw 'CD' Pw# @5% Patented Oct. 3, 1950 TRACTOR-MOUNTED LOADER `Carl `W. Mott, Lake Ozark, Mo., assignor to International Harvester Company, a, corporation of New Jersey Application July 29, 1948, Serial No. 41,341

7 Claims.

This invention has to do with hydraulicallyoperated apparatus and concerns particularly an improved type of tractor-mounted loader and a hydraulic system adapted to supply operating force thereto from the tractor engine.

A general object of this invention is the provision of a tractor-mounted loader capable of employing a hydraulic ram with which the tractor is normally equipped, together with a supplemental ram or motor for elevating a load carrier. In the present embodiment this is done by connecting the supplemental ram into the hydraulic circuit of the normally equipped ram and providing complemental mechanical connections of these two rams with the load carrier, wherefore a single control for the normally equipped ram suffices to control both rams. Economy is realized because of using the regularly provided universally used hydraulic equipment for controlling and transmitting power from the tractor engine to the load carrier. Also, the complete hydraulic system retains desirable operating characteristics of the regularly supplied system, namely, that the parts hydraulically operated are caused to move correlatively with the control member both in distance and direction. A connection between the normally provided ram and the control valve causes closing of this valve upon movement of the ram plungerin accordance with an initial movement of the control member and thereby terminates liuid delivery to both rams, although during operation of the normally provided ram, fluid is also supplied to the supplemental ram which acts as a booster and is held in operating phase with the normally provided ram by the operating connections of these two rams with a common power output structure for lifting the load carrier.

The present embodiment illustrates a tractor engine as a power developing unit from which power is transmitted hydraulically to a power output structure which has operating connections with a load carrier of a tractor-mounted loader.

It is contemplated, however, that this principle of employing a servo-acting ram in control of a control valve which initiates operation of .the ram, together with a supplementary ram utilizable of its force output complementally with the servo ram is equally applicable in other power transmitting systems;

A further object is the provision of a tractormounted loader wherein there is a power output structure mounted at an end of the tractor for rocking about a horizontal axis transverse thereto, a load carrier boom pivotally connected with the tractor for vertical movement and projecting beyond such end of the tractor, and cam means constrained for rocking with the power output structure to cooperate with a cam follower on the boom for raising the boom when the power output structure is rocked.

Another object is the provision of a rockable structure according to the preceding objects, wherein there are operating arms projecting respectively upwardly and downwardly therefrom, hydraulic rams mounted on the tractor between its ends, a thrust link operably connected between one of the rams and one of said arms, and a tensile force exerting link connected between the other ram and the other of the arms for complementally rocking the power output structure when the rams are energized.

Another object is the provision of a novel mounting assembly for the power output `structure at the end of the tractor, such mounting assembly comprising a pair of elongated frame members extending along opposite sides of the tractor and having upper end portions beyond such end of the tractor for pivotally supporting a rockable element projecting therebetween and supported thereon.

The above and other desirable objects inherent in and encompassed by the invention will be more fully comprehended upon reference to the ensuing description, the appended claims, and the annexed drawings, wherein:

Fig. 1 is a side elevational view of a tractor having a preferred embodiment of the invention assembled thereon.

Fig. 2 is a plan View of the tractor and apparatus mounted thereon in Fig. 1. i

The invention is illustrated in Figures,Y 1 and 2 in connection with a power developing unit in the form of a tractor II. This tractor which is of the four-wheel type has rear traction wheels I2 and front dirigible wheels I3. In Figure 2, rear axle housings Ill and I5 are shown projecting oppositely from a diierential housing lli which is offset to the left, with respect to an operator upon the tractor, of the centerline of the tractor running gear. A body Il projecting forwardly from the differential housing iti is also offset to the left from the running gear centerline. The body l1 has an engine E upon a front portion thereof, superposed by a hood I8 from which a fuel tank I9 projects rearwardly.

A loader apparatus for being operated by power transmitted thereto from the tractor engine comprises a pair of booms 2l and 22 pivoted their rear ends t0 opposite sides of the tractorbody.

The pivot connections of the booms 2| and 22 are designated 23 and 24. Each boom has a forwardly extending straight section rearwardly of the tractor front axles 25 and 25. Immediately above the tractor front axles, the booms bend downwardly and project forwardly for mutually carrying a loader fork 21 on their front ends. The front ends of the booms are rigidly interconnected by a cross piece 28, and pivot connections 29 are provided respectively between the front ends of the booms and opposite ends of the loading fork.

A vertical member 3i attached rigidly to the back of the loading fork has a latch pin 32 which when received in a notch 33 of al pivcted latch member 34 holds the loader fork against pivotal movement clockwise as viewed in Figure l whereby its tines 35 are maintained in a horizontal load-carrying position. After the booms have been elevated as explained hereinafter to some such position as that illustrated by dotted lines in Fig. l, a manually exerted pull on a latch cord 36 by the operator will release thelatch 34 from the pin 32 against the force of a spring 31 and permit the loader fork to pivot te the dumping position illustrated by the dotted lines. Reestablishment of the load-carrying position is incurred by the operator pulling upon a cord 38 which causes counter-clockwise movement of the loader fork and replaces the latch pin 32 within the notch 33 where it lodges for being retained within the notch by the spring 31.

Power derived from the tractor for raising the front ends of the booms 2i and 22 and the loader fork 21 is transmitted to the booms through a hydraulic power transmitting unit 4l and a rockable power output structure 42 mounted on the forward end of the tractor for rocking motion about a horizontal axis extending transversely to thev tractor. The power output structure 42 includes a tubular elongated member 43 constituting a portion thereof and pairs of apertured ears 44 and 45 projecting radially from the member. These pairs ofl ears 54 and 45 straddle respective upturned end portions 45 of a mounting assembly for the rockable output structure. The apertures in the ears 54 and 45 align with apertures in the upturned portion 45 and pins 41 inserted in these apertures for pivotally connecting the elongated portion 43 of the power output structure in pendulous fashion to the mounting assembly therefor.

The mounting assembly for the roclable power output structure 42 comprises elongated frames 48f and 49 extending lengthwise of and disposed v upon opposite sides. of the tractor body. Frame 48 as illustrated in Fig. 1, includes an elongated member attached at its rear end to a bracket 52 on the rear axle housing of the tractor. rIhis member 5I projects forwardly beyond the front axle upon which it re-sts and includes the upturned front end portion 45. A reinforcing bar 53 extends between the upturned portion 46 and a rearward portion of the 'bent element 5I and is welded thereto at its two ends respectively at 54. and 55. The side frame 39 is constructed quite similarly to the side frame 48, the back end thereof being connected with the rear axle housing I4 by a bracket 56 and a forward portion of such side frame member resting upon the left front axle 26.

The right end of the rockable power output structure 42 has a long cam arm 58 rigidly connected therewith. The upper edge of this arm 58 constitutes a cam profile cooperable with prising a ported and channelled casing E3.

a flange roller 59 constituting a cam follower mounted upon the boom 22, A portion of the cam arm profile extends downwardly and rearwardly beyond the cam follower 59 while the boom is in its lowermost position and a further portion 59 of such profile continues from the downwardly and rearwardly projecting proiile and is curved to extend first horizontally and then upwardly in a rearward direction.

The hydraulic power transmitting unit comprises a pump 6l mounted on a side of the engine and driven from the engine by a power train not shown. Fluid is discharged from the pump through a conduit 62 into a control valve com- All parts of the hydraulic power transmitting unit 4I including the pump 6I and the control valve l 63 may be identical with the corresponding mechanism disclosed in United States Patent No. 2,399,756, issued May 7, 1946, to Carl W. Mott. In View of the details of the hydraulic power transmitting unit being minutely disclosed in said patent, a mere general reference to certain parts of the unit will suffice for the present disclosure. A control member 64 of the valve 63 is swingable fore and aft over a quadrant B5 by manipulation of an operator occupying the tractor seat B6. The valve 53 is operable to determine whether iluid introduced thereto through the conduit 62 is directed into a channel 66 communicating with the rear end of a ram cylinder 61 or whether fluid from the conduit 62 is introduced into a passage 68 leading to the front end of the ram cylinder 61. A ram plunger 69 is connected by a connecting rod 1l with an arm 12 on a rock-shaft 13 mounted transversely of the tractor body. When fluid is introduced into either end of the ram cylinder 61, the valve 63 will cause com-- munication between the opposite end of the cylinder and a conduit 14 leading to the inlet side of the pump 6|.

The ram S1-59, in addition to rocking the rock-shaft 'I3 so that power is available from a rock-shaft arm 15, also serves as a servo motor for controlling shut off of the valve 63. This control of the valve 63 is effected through a link 16 which is connected between the rock-shaft arm 15 and an arm 11 with which a valve controlling shaft 18 is constrained for pivoting. The operation of this hydraulic power transmitting unit is such that when the manually operated member 64 is moved forwardly or rearwardly over the quadrant 65, a corresponding movement will be imparted to the rock-shaft arm 15 by the hydraulic ram 61-69 and the rock-shaft 13 with which the piston rod 1| of said ram is operably connected. After the rock-shaft arm 15 has been moved a distance and direction correlated with the distance and direction of the movement of the member 64, the linkage 15, 11, and 18 will be effectivev for closing the control Valve and causing the rock-shaft arm 15 to be hydraulically locked. During this time that the valve is closed, it will causev establishment of a direct connection between the conduits 62 and 14 whereby the pump 5l can continue operation at relatively low bypass pressure. That part of the hydraulic power transmitting unitV thus far described isV commercially produced, wherefore the hydraulic ram @1 -59 may be regarded as a normally provided ram. This ram is operable through the rock-shaft arm 15 operated thereby and a thrust link 19 to urge the power output structure 42 to rotate clockwise as viewed in Fig. 1. An upwardly projecting arm of the power output structure is pivotally connected at 8|)a with the front end 'of the thrust link 19. According to this invention, however, the hydraulic system of the hydraulic power transmitting unit is tapped into at conduits E6 and 68 by conduits 8| and 82 which lead to a supplemental ram or motor 83. The back end of the cylinder of the ram 83 is pivotally connected to the tractor body by means of a bracket 84 and a pivot pin 85. The piston 83a of the ram 83 is connected by a tension link 86 with the lower end of an arm 87 projecting downwardly from the power output structure. By tracing the conduits in Fig. l, it can be ascertained that when fluid under pressure is introduced into the conduit 66 and hence into the rear end of the ram cylinder 6l for urging the ram piston 69 forwardly and thereby urging the rock-shaft arm to rock clockwise. fluid will be concurrently introduced into the conduit 8| and thence into the front end ofthe ram 83 for forcing the plunger 83a rearwardly and creating a tensile force in the link 86 concurrently with the thrust force exerted through the link 19 by the rock-shaft arm 15, and these two end forces in the links I9 and 86 operate complementally for rocking the power output structure 42 clockwise.

Forward manipulation of the control member tid causes introduction of uid under pressure into the passage 66 for energizing the two rams 61-69 and 33 in a manner just described for rocking the power output structure clockwise. This causes the cam arm 58 to raise the cam follower 59 and to cause upward swinging of the motor booms 2| and 22 whilethe cam follower rolls rearwardly upon the cam profile. The operator will predetermine the elevation at which the loader fork 2? is raised in accordance with the distance he manually advances the control member 64 forwardly along the quadrant 65. Whenthe loader fork reaches its predetermined eevation the servo -motor 67-69 will have operated the linkage i6, Ti, and 'i8 for closing the valve and terminating further delivery of fluid into the rams. It is immaterial that only the ram 61--69 is connected with the control valve 63 for shutting it off by servo action. The bore and stroke of the supplemental ram 83 is not critical because these two rams are connected in xed phased relation by their operating connections of the links i9 and S6 with the rockable power output strucf ture. So long as the plunger 69 of the ram 6?--69 continues to move in the attainment of a position predetermined by manual setting of the control member 64, iiuid will be introduced into the rear end of the ram cylinder 6'1 and into the iront end of the ram 83, and fluid entering the ram 83 will supplement the force of the ram l-SQ in rocking the power output structure 42. Diverting of uid from the ram 61--69 into the ram 83 under these conditions would, of course, diminish the speed with which the ram plunger 68 would otherwise move (assuming the pressure to be sufficient to enable this ram to overcome the resistance imposed upon the rockable structure by a loaded boom structure) but ultimately suicient iluid will be introduced into the two rams to cause movement of the ram plunger 69 into the position for causing shut off of the valve B3. Use of the supplemental valve ram 83 diminishes the required necessary unit pressure of fluid in the system for overcoming any given resistance to rocking of the power output structure. Thus the ram 83 acts as a booster for aiding the ram tii-EQ and the hydraulic system employed for the two rams is such that the operating charac- 6 teristic `whereby the movements of the ram plunger 69 are correlated in direction and distance with the movements of the control member 64 is preserved.v

The foregoing explanation of the introduction of uid in the two rams has presupposed the condition of the control member Ell-i being moved forwardly for causing raising of the loader `fork. However, the same conditions iprevail when the control member is moved rearwardly in the respect that the two rams are tied together through the power output structure for maintaining their iii-phase relation and in the respect of the position of the ram plunger KiSS-and the position of elevation of the loader fork remaining correlated with the position of the control member 613 upon its quadrant.

In Fig. l it will be noted that the cam arm -58 imposes force upon the cam follower 59 by means of a relatively short force arm when initially raising the loader fork 2i to break its load loose from a Ipile of material from which the load is boing removed. The relatively short force arm continues to be utilized by the cam arm 53 until the load is broken loose and there has been a substantial acceleration in the speed of movement of the ascending load. Thereafter the force necessary for continuing upward movement of the load diminishes, wherefore the profile of the cam arm is so designed that the effective force arm acting upon the cam follower 59 increases to cause a direct increase in the speed at which the load is raised. The operating speed of the apparatus is effectively increased by so designing a cam arm that upward movement of the loader fork is at an increased speed after the load has been broken loose and is susceptible of being elevated at a rapid rate.

i Having thus described the single preferred embodiment of the invention with the view of clearly defining and illustrating the same, I claim:

1. In combination, a power developing unit in theforrn of a tractor which comprises transversely extending rear axle housings, a body extending forwardly from such housings and an engine upon a forward part of such body; an hydraulic power transmitting unit comprising a pump driven from said engine, an hydraulic motor mounted on said body rearwardly of the engine and including a work member movable when subjected to fluid under pressure delivered by the pump, conduit means communicative between the pump and motor, and control valve means interposed in the conduit means, said control valve means being manually settable to subject the motor to such iiuid via the conduit means and resettable by ensuing movement of the motor work member for terminating subjection of the motor to such iiuid incident to movement of the work member an amount determined by the manual setting of such valve means; a rock-shaft mounted on the tractor body rearwardly of the engine; means connecting the rock-shaft with said work member so it will be rocked thereby When the work member is moved; a power output structure; means mounting said structure forwardly of the tractor engine yand for rocking movement about a horizontal axis extending transversely of the tractor body; means connecting the rock-shaft with the output structure for rocking the same pursuant to movement of the motor work member; a scoop loader boom. structure pivotally connected with the rear axle hous-l ings and projecting forwardly beyond the rockable power output structure;` means operated by rocking motion of the output structure for raising the forward part of the boom structure; a supplemental hydraulic motor mounted on a side of the tractor body and having a work member movable when subjected to fluid under pressure delivered by the pump; means connecting the supplemental motor work member with the rockable power output structure for movement thereof complementally with the action of the first hydraulic motor; and conduits connecting the supplemental motor with said conduit means to cause subjection of such supplemental motor to fluid pressure coterminously with the subjection of the rst motor to such fluid pressure.

2. In combination, a tractor having a fore and aft extending body, a loader boom lpivoted on a rear portion of the tractor and projecting forwardly beyond said body, a rockable structure mounted on the tractor forwardly of said body for rocking motion about a horizontal aXis eX- tending transversely of the body, a c'am follower on the boom rearwardly of the rockable structure and disposed below the pivot axis of the rockable structure, a cam arm constrained for rocking motion with said structure and projecting rearwardly therefrom beneath the cam follower, said cam arm having a profile cooperating with the follower and of which a portion projects downwardly and rearwardly from the follower while the latter is in a lowered position, said profile portion being operable'to raise such follower and the forward portion of the boom pursuant to rocking of the rockabfle structure in the direction raising the cam arm, and means on the tractor for rocking said structure.

3. The combination set forth in claim 2, wherein a further portion of the cam profile continues from the downwardly and rearwardly projecting cam tpronle portion and is curved to extend rst horizontally and then upwardly in a rearward direction.

4. In combination, a tractor comprisinga fore and aft extending body; an auxiliary power transmission system of an hydraulic type installed upon the tractor and comprising an hydraulic ram including ya plunger, an hydraulic circuit for controlling the pressure of fluid upon the ram to determine direction and amount of movement of the ram plunger, and a manually operated control including valve means in the hydraulic circuit and a control member manipulatable of the valve means to initiate movement of theV ram plunger in a direction correlated with the direction theA control member is manipulated, and meansV connecting the ram plunger with the valve means to control the same for interrupting such initiated movement of the ram plunger after movement thereof anv amount correlated with the amount of control member manipulation; a rockable structure mounted on the tractor forwardly of said body and rockable aboutV a horizontal axis extending transversely of such body; a loader boom pivoted on a rear part of the tractor and projecting forwardly f the body; a cam follower on the boom rearwardly of the rockab-le structure; a cam arm constrained for rocking motion with the rockable structure and projecting radially therefrom into cooperative relation with the cam follower for elevating the follower and the forward endV of the boom pursuant to rocking of the structure; a supplemental hydraulic ram mounted on the tractor rearwardly of the rockable structure; conduit means communicating between the supplemental ram land said hydraulic circuit for causing application of iluid pressure upon the supplemental ram for moving its plunger concurrently with movement of the rst ram plunger and in a correlated direction. of movement; and operating links connected respectively with the ram plungers and with the rockable structure for complementally rocking the structure in an amount and direction correlated with the amount and direction of manual setting of the control member.

The combination set forth in claim 4, wherein there are operating arms projecting respectively upwardly and downwardly from the rockable structure, wherein there is a rock-shaft mounted transversely of and upon the tractor body above the supplemental ram and rockable by the rst ram, a rock-shaft arm constrained for rotation with said rock-shaft and projecting up- Wardly therefrom, a thrust link connected between the upper end of said rock-shaft arm and the upwardly Yprojecting arm on the rockable structure, and a tension link connected between the supplemental ram plunger and the down- Wardly projecting arm of the rockable structure.

6. In apower output structure for use upon a tractor having a fore and aft extending body and laxles projecting laterally outwardly from the body adjacently to an end thereof, a mounting assembly comprising a pair of elongated frame members disposable lengthwise of the tractor on opposite sides thereof for attachment thereto, said frame members having upturned end portions and being of a length to project such end portions beyond an end of the tractor body while other portions of said members are supported respectively on said axles, and a rockable structure extending transversely of the tractor and pivotally connected with said upturned end portions of the frame members, and means on the roclable structure for imparting rocking motion thereto. '1.l In a @power output structure for use upon a tractor having a fore and aft extending body, a mounting assembly comprising a pair of elongated frame members disposable lengthwise of the tractor on opposite sides thereof for attachment thereto, said frame members having rockable structure supporting end portions and being of a length toproject such end portions beyond an end of the tractor body, and a rockable structure extending between said frame end portions for pivotal support thereby, said rockable structure having an elongated portion extending between the end portions of the frame members `and parts projecting transversely from such elongated lportion into respective pivotal connection with the frame end portions to cause the elongatedY portionY to swing pendulously pursuant to rocking thereof.

CARL W. MOTT.

REFERENCES CITED 'Ihe following. references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,292,029 Paine Jan, 21, 1919 2,173,158v Corbett Sept. 19, 1939 2,398,119 Sauder Apr. 9, 1946 2,433,086v Borgelt Dec. 23, 1947 2,465,476 Pokorny et al. Mar. 29, 1949 2,469,615 Templeton May 10, 1949 FOREIGN PATENTS Number Country Date 416,019 Great Britain Sept. 4, 1934 

